Prior to the present invention, two problems with controlling the rubber squeegee were prominent.
First, the means of holding the rubber squeegee in place was accomplished by five adjustable screws. These five screws would push into a flat piece of aluminum metal. Adjustment of the five screws continued until two conditions were met: (1) the rubber squeegee was held in place; and (2) the surface of the rubber blade was flat. While this mechanism worked, it had several disadvantages. Each time a new rubber blade was inserted into the holder and tightened in place the aluminum material deformed. The deformed aluminum distorted the squeegee blade producing uneven printing.
Second, the method of leveling the squeegee was imprecise. The leveling technique was accomplished by aligning the squeegee holder such that it was parallel with the printing surface. Once this was completed a screw was tightened in order to hold this position. Because the squeegee holder could move freely until it was tightened down, the very process of tightening tended to twist the squeegee holder. This twisting was cause by the torque generated by irregularities in the screw. Another means of performing the leveling function uses a spring and ratchet combination which provides a greater degree of control. However, this method is susceptible to spring fatigue over use.